Dry-cell electrode



Sept. 18,1928. 1,684,735

H. D. HODGE DRY CELL ELECTRODE Original Filed March 24, 1925 INVENTOR Howard D. Hodye BY M p z w ATTORNEYS Patented Sept. '18, 1928-.

UNITED STATES PATENT OFFICE.

HOWARD ID. HODGE, DECEASED, or New YORK, N. Y., BY- nn'vma WELLS HOIDGE,

ADMINISTBATRIX, or BRIDGEPORT, CONNECTICUT, ASSIGNOR 'ro nuaenss BAT- 'rnmz COMPANY, on MADISON, WISCONSIN, A CORPORATION OF WISCONSIN.

' DRY-CELL ELECTRODE.

original application filed March 24,. 1925, Serial No. 17,858. Patent No. 1,638,995, dated August 16, 1927. Divided andthis application filed July 17, 1926. Serial No. 123,236.

In the manufacture of dry-cells, such as are commonly used in battery hand lamps'and in the radio industry it is a common practice to provide a zinc electrode 1n the form of a seama less cup formed from aflat blank by a series of drawing, pressing or ironing operations. A

suitable method for thus shapin zinc cups from a flat zinc sheet is disclose in United States patent to L. Maisel, No. 1,375,305 to issued April 19, 1921. v

Such seamless zine cups serve not only as one electrode of the. galvanic couple, but also serve as a container for the more corrosive ingredients of the dry-cell. I

The succession of drawing or sha ing operations through which a flat sheet zinc must pass before it can be formed into the finished cup leaves a ragged edge around the top ofthe cup; It has been standard practice A in the manufacture of drawn zinc cans for drycells to draw or form them to a length longer than is desired and then tocut' the cup to its large rotatable cylinder and there tumbling them in the presence of 'a cleaning solution adapted to dissolve oil the lubricant. However, this tumbling of the cups in large quantity is likely to and often does result. In

damaging the square trimmed edges oi the I inclusive represent different relative posicups often forming small notches in the edge by forcing the metal inward, so that it pro- 40 trudes as a small projecting ear," or roughness. Similarly, when the cleaned cans are dumped into barrels and are carted about, as

. a part of regular factory manipulation, or

are dumped into bins for storage, the same at defacement of the exposed edges of the cans is likely to take place, and often does take lace.

This reduction in the effective diameter of the can because of notches formed in the edge to during previous handlin of the can often interferes with the speeFy performance of subsequent operations. orexample, it is customary to insert into the zinc cup a paraffined paper washer and when there are inward projections on the edge of the cup they prevent the easy placement of the washer and sometimes make its insertion entirely impossible.

It isan object of the present invention to rovide a dry-cell cup with its upper edge so velled or tapered as to facilitate the intro-. duction of other elements of the cell, and so shaped that a blow on the edge of the cup, such as might be experienced by it in tumbling and rough handling, would show itself .not as a'lip or projection into the inside of the can,- but as a mere "turning over of the edge toward theoutside of the cup.

' It is a further object to produce seamless zinc cups of uniform length and without the irregularities necessarily incident to the hand manipulation now practiced for trimming vthe cups on a trimming lathe.

l o attain the foregoing objects and others" which w1ll be made clearfrom the subsequent detailed description, there has been devised a method whereby the trimming operation ac' companies a drawing operation, preferably the last re-draw, that trimming operation being carried out by the dies used for drawing, those dies beingso shaped as to pinch oil the tube of metal after the cup has been shaped to the desired length and diameter.

By thus correlating-the trimming tothe drawing there is a substantial saving in han-f dling and in subse ue'nt operations heretofore regarded as essential before the cup could be assembled into a dry-cell.

tions of a pair of dies in which a zinc cup is Fig. 6 is a cross section of a dry-cell embodying a seamless zinc cup with a bevelled edge,

this representation being somewhat diagrammatic in so far as concerns the details of elements other than the cup. Fig. 7 is a fragmentary enlargedview showing the edge of a seamless cup that has been trimmed by pinching off the excess metal between a pair of dies like those shown in- Figs. 1 to '5, inelusive.

Zinc is such a brittle metal that it cannot be shaped into dry-cell cups of usual dimen- In the accompanying drawings, Figs. 1 to 5 being formed and simultaneously trimmed.

i wardly to form a shoulder 4, which, in conjunction with die 2, serves to shear or pinch off the upper ragged edge of the zinc can and thus effect the'desired trimming and the desired bevelling of the edge.

Fig. 2 of the'drawings shows the progress of plunger 1 into die 2 and shows how the ,zinc cup is drawn, or more strictly speaking is ironed, into the annular gap between the dies thus reducing the diameter of the cup and increasing its length. In other words, the clearance between dies 1 and 2 is substantiall. equa-l'to the thickness of the zinc wall of t e cup 3 of Fig. 1. After the plunger has progressed far'enough through the die, its bevelled shoulder 4 comes into forcible en- .gagement with the inner face of the moving zinc cup,' and inasmuch as the diameter of the plunger above the shoulder 4 is substantially equal to the opening in die 2, there will be a shearing or pinching action on the relatively soft zinc with resultant complete severance of the end portion 5 of the cup, as

shown in Fig. 3. On the return stroke of theplunger the trimmed zinc cup 6 enga es the annulardie 2, and b it is stripped from plungerl and is thus cc to drop out of the machine. On completion of the upper stroke the severed trimming 5 strikes a stripper 7 and by it is removed from the plunger., All of the cups produced by such a drawing or redrawing action are of exactly the same length and'have; their edges neatly bevelled. Any subsequent tumbling or rough handlin is not likelyto produce an. inward denting o I the extreme outer edge of the cup to an extent greater than is indicated at 8 in Fig. 7. It would require a very hard blow on the edge of the cup to fold it inward far enough to lessen the effective inner diameter of the cylinder. i

- By thus leaving the seamless zinc cup with a flaring upper edge, the subsequent factory manipulations are simplified.

In Fig; 6 the zinc electrode 6 serves as 2).

container-for the usual carbon rod 9, the depolarizing mixture 10 in its cheese cloth envelope 11 and the gelatinized paste 12, as in usual practice. There is an air gap 13, and above the air gap and fitting snugly within the zinc cup is a paraflined paper washer 14 which encircles the carbon rod and serves as the'bottom of a pocket into which pitch or sealing wax 15 may be'poured in hot condition to form-an air tight seal between the zinc cup and the carbon rod 9 and its brass terminal cup 16.

In factory operations on a large'scale these paraflined paper washers 14 must be put in at a rapid rate, and when in position should lie horizontal and should fit snugly against the zinc wall. The bevelling of the zinc edge and the freedom from inwardly pro ec ting tongues or corners of zinc contribute to the spe ed at which the washers can be inserted and lessen the dangerthat the washers will go in on a slant, or will be torn or bent in the operation of crowding them down over the brass cap 16 into their final position within the cup.

' The relative sizes and proportions of the elements shown in Fig. 6 are not of importance, for the invention is applicable to drycells of differing shapes and sizes.

This application is a division of the copending application, Serial No. 17,858, filed March 24th, 1925 (now Patent No. 1,638,995, granted August 16th, 1927). i

What is claimed is:

1. A dry with a bevelled surface formed at its upper edge on the inner wall whereby lessening of the effective diameter of the cup due to tumbling or rou h handling is prevented without increasing t e external diameter of the cup, and a relatively thin insulating washer snugly fitting in said cup below said bevelled edge.

2. A dry cell having a seamless zinc cup with a bevelled surface formed at its upper edge on the inner wall whereby lessening of the effective diameter of the cup due to assembling and rough handling is prevented without increasing the external diameter of the cup, a carbon rod in said cup, and a relatively thin insulating washer encircling said rod and fitting snugly in said'cup below its bevelled edge.

cell having a seamless zinc cup I In testimony whereof I atiix my signature.

ELVIRA WELLS HODGE, Administratfim 0f the Estate of Howard odge, Deceased. 

